Originally Posted by
subgrade
As long as the rear cog is still inside the frame dropout, the belt/chain still crosses the chainstay. The elevated (or dropped, as in modern gravel bikes) chainstay is a solution for chainring / tire clearance, nothing to do with the chain or belt.
To solve the frame splitting problem there are two options - move the rear cog outboard the frame, or get rid of both chainstay and seatstay on the drive side. Both seem possible, but would be rather sophisticated solutions and most probably are far from cost effective.
Nah, the bike above can take a belt if so desired the chain stay attachment point is above the chain , tensioning it, not so easy. Thing is a split seat stay is probably cheaper, but an IGH is more expensive, so derailleurs and chains it is.